Coffee maker



Oct. 9, 1951 P. E. wlLLMAN 2,570,997

COFFEE MAKER Filed Nov. 16, 1946 2 Sheets-Sheet l INVENTOR. PHILIP E.WILLMAN Oct. 9, 1951 l P. E. wiLLMAN 2,570,997

COFFEE MAKER Filed NOV; 16, 1946 2 Sheets-Sheet 2 INVENTOR. PHILIP E.WILLMAN BY f//w Patented Oct. 9, 1951 oorrEE MAKER Philip E. Willman,Chicago, Ill., assigner to McGraw 'Electric Company, Elgin, Ill., acorporation of Delaware Application November 16, 1946, Serial No.710,246

3 Claims.

My invention relates to coffee makers and particularly. to a vacuum-typeof coiee maker.

An object of my invention is to provide a novel form of vacuum-type ofcoffee maker.

Another object of my invention is to provide a novel form of vacuum-typeof coffee maker in which the vacuum-type of operation is used but in`which the brewed coffee does not return to the water container.

Another object of my invention is to provide a vacuum-'type coffee makerin which the tube extending from the water container to the coffeecontainer is utilized to receive Aand hold the coiee grounds. Y

Other objects of my invention will either be apparent from avdescription of several forms of devices embodying my invention or willbe pointed out in the course of such description and set forthparticularly in the appended claims.

In the drawings:

Figure 1 is a view in longitudinal vertical section through a coieemaker embodying my invention, and,

Fig. 2 is a view in longitudinal vertical section through a modied formof coffee maker embodying my invention.

Referring first of all to Fig. l of the drawings, I have thereillustrated a vacuum-type of coffee maker designated generally bynumeral I I, which comprises a lower water heating pot I3 and an uppercoffee receiving bowl I 5 as well as a handle Il and a cover member I9.

Since the coffee maker embodying my invention is to operate as avacuum-type of coffee maker, I provide the water-heating pot I3preferably of aluminum 2l, preferably making the same of cast aluminum,the walls thereof being made as thin as it may be possible to make them.The upper end portion of water-heating pot I3 is p-rovided with a recess23 therein, this recess being provided with smooth inner surfaces,particularly the vertical surface as Well as the horizontal surface 25.

The upper coffee bowl l5 may be made of drawn aluminum and it is to beunderstood that the t of upper bowl I5 in the recess 23 at the upper endof the water-heating pot I3 is such that a steam-tight joint will beprovided.

The upper bowl I5 is provided with a pouring spout 21 and cover memberI9 having a handle 29 secured thereto is also provided. While cover I9may be of any suitable or desired material, I have shown it to be madeof an electric-insulating material which has been molded to the de siredshape.

The handle Il is also preferably made of electricand heat-insulatingmaterial and may be held in proper operative position against theheating pot I3 by a plurality of short-machine screws 3| and 33, thesescrews extending into lugs 35 and 3l respectively which are cast on thewater-heating pot I3. I wish to here point out that the brewed coieedoes not iiow into rthe lower heating pot I3 but is adapted to beretained in the upper bowl I5. This will make the weight, to be liftedby an operator, positioned in the upper end portion of the coffee makerso that I prefer to make the handle Il suiciently long vertically of thecoffee maker so that when it is in use and is handled as for pouringoutthe coiee to fill one or more cups, it will be well balanced.

I provide an inner centrally-positioned tube 39 which extends throughthe bottom wall 4I of the upper pot I5 through an opening 43 centrallylocated in the bottom wall 4I. I may braze or Weld tube 39 in fluid-typeengagement with the bottom wall 4I.

I provide further a tube 45 which is provided with an open lower end 41and with an open upper end 49, the upper end 49 being preferably madesomewhat enlarged relatively to the diame eter of the rest of tube 45.

I provide a lower perforate member 5I which is preferably adapted to bemoved into engagement with the inside surface of tube 45 and to flttightly therein.

At the upper end of tube 45 I provide an enlarged portion 53 and placeinthe upper end of said portion 53 a perforated filter 55 having ahandle 5l secured thereto.

I desire it to be understood that tube 45 in tube 39 is steam-tight.Since some of the water in heating pot I3 is apt to be vaporized tocause upward flow of the heated water from pot I3 into bowl I5 asthrough tube 45, the upper lter 55 is adapted to be held by a bayonetjoint 59 provided at the upper enlarged end 49 of tube 45. In order toensure that water shall not flow upwardly prematurely into bowl I5through the coifee grounds which are adapted to be posi` tioned in tube45, I provide a small opening 6| in tubes 45 and 39 positioned justabove the bottom wall 4I of bowl I5. As is well known, the provision ofsuch a small opening permits the escape of small quantities of steamgenerated by .the water in the heating pot I3 as long as a certainpredetermined quantity of steam is not exceeded. But when thetemperature of the water in pot I3 rises so that a relatively-largeamount of steam is generated, this steam will no longer be able to leavethrough opening 6I and therefore the main body of the hot water in potI3 will move upwardly through the coffee grounds which have beenpositioned in tube 45 and from which it will flow into the upper bowlI5.

Referring now to Fig. 2 of the drawings I have there shown amodification Vof a. coiee ,maker embodying my invention. In thisconstruction I do not use two partially co-extensive tubes but use onlya single tube 93 which is adapted to be welded into opening 43 in thelower wall 4I as by welding seams G5. Only such other 'selfevidentmodifications as are necessary to provide an operative device havebeenmade in the construction of the modification shown in Fig. 2 asdiierent from that shown in Fig. 1. Substantially the same remarksasmadehereinbefore in connection with the operation of the device Y,

illustrated in Fig. 1 apply equally well to the device shown in Fig. 2which has the further advantage that the t of tube 45 in tube V-39fisnot necessaryisince yno -tube 39 is 'used in the Vdevice shown inFig.,.2 of `the drawings.

.I may, however, yreplacethe iilter 55 of Fig. 1 with amodifi'cationcomprising aniupperor outer metal frame-57i comprising aplurality ofradially extending arms. andan innerr cloth filter 59. The metal frameis adapted to -fit on the upper end :of the enlargedpart 53 with afsnapaction, the peripheral lportion holding the Ncloth lter 39.

It will :be noted lthat the upper lter Vis -o'f relatively largediameter and this isfound ad visable topermit outflow of- 'the coffeeessence mixed with hot water from the lower container :IBw-ithout.causing too much pressure to 'begeneratedin container I3 and tube 115or B3 below the coffee grounds.l

Upon tests ymade upon a sample coffee maker embodying these details itwas found that the color of the -extract produced at the start of theupward. Iflow of water throughth'e coife'e groundsfin;tube4'5 `or 53 wasquite dark and that the color thereof became lighter the longer the owof water occurred. VIt was also found 'that it was desirable -to holdthe top "lter Vnieansin proper .operative position at the upper end ofeither tube 45 or tube 63 andiif'n'ec'e'ssary a light bayonet joint maybe provided tol'holdthe upper lter :55 :or sand 69 in its position inthe upper endxofeither tube 45 or upper tube 53.

Various modifications may be made in the device embodying my inventionwithoutdeparting. from-,the spirit and scope 'thereof Yand all suchVmodifications clearly coming within. the scopefof `.the appended claimsshall beoons'idere'd as part of my invention.

I claim as my invention:

1. A coffee maker, comprising in combination a lower heating pot, anupper essence-receiving bowl fitted steam-tight to said lower pot, anarrow, cofee-grounds-containing tube connected steam-tight in thebottom of said upper bowl and extending substantially the combinedheight of..said intertted pot and bowl, whereby said tube constitutes vaduct extending from the bottom interior of said pot to the top interiorof said bowl, and filter means at the top and bottom of said tube forretaining coffee grounds therein while permitting a flow of liquidtherethrough.

2. A .coffee maker comprising in combination, a flower .heatingcompartment, an upper essencereceiving compartment thereabove, a narrowcoifee-grounds-containing tube extending substantially the combinedheight of said two compartments whereby said tube constitutes a ductextendinLT from the bottom interior of the lower compartment to'thetopinterior ofthe upper compartment, said lower compartment beingfot'herwise closed, 'so' that pressure therein rcan force liquidtherefrom `up through said tubel into said upper compartment, and filterin'ejansv at "both the topand bottom of said tube for .retain- "in,coffee grounds therein while rpermitting liquid 'to "flow therethroughand 'contact'coe'e grounds substantially throughout the full length diAsaid tube.

3.1".1he coffee maker of claimfl wherein there is 'included ."a handle"fastened Ito said ilowe'npot for v"supporting said pot and bowltogether, ,Tand said handle extends up beyond the .top foifsafid lowernot, alongside said upper bowl to a'position near the top of 'said.upper bowl.v I

, PHILIP 'WHILE/IAN. Y

REFRECES VfoIrrED The following references are Yof record in V"the nieof this patent: Y i UNITED 'STATES PATENTS.,

